1. Field of the Invention
The present invention generally relates to a steering assist system for a vehicle. More specifically, the present invention relates to a steering assist system for a vehicle that employs an autopilot device.
2. Background Information
A conventional marine vehicle generally includes a rudder device, a steering device, and an autopilot device (see U.S. Pat. Nos. 5,235,927, 5,253,604, and 6,311,634, for example). The rudder device mainly has a rudder and a steering cylinder. The steering cylinder is coupled to the rudder, and actuates the rudder. That is, the steering device manually operates the rudder device to control a heading of the marine vehicle. The steering device mainly has a helm and a helm pump. The helm is manually operated by a helmsman, thereby operating the helm pump according to a steering operation of the helm. The helm pump is hydraulically coupled to the steering cylinder of the rudder device. Hence, the helm pump operates the steering cylinder of the rudder device according to the steering operation of the helm, thereby actuating the rudder.
As understood in the art, the autopilot device electrically operates the rudder device to control the heading of the marine vehicle to automatically track a preset target course. The autopilot device mainly includes an operation unit, a heading sensor, a controller and an autopilot actuator. The controller is electrically coupled to the operation unit, the heading sensor and the autopilot actuator. The autopilot actuator is hydraulically coupled to the steering cylinder of the rudder device. The controller controls the autopilot actuator based on signals from the operation unit and the heading sensor, thereby operating the steering cylinder of the rudder device. Furthermore, the autopilot device also allows the helmsman to input a steering command with keys or dials disposed on the operating unit for steering the marine vehicle.
With the conventional steering device, the helm can be used to steer the marine vehicle in an intuitive manner. However, the steering device requires some physical effort by the helmsman to operate the helm. On the other hand, the autopilot device electrically steers the marine vehicle without requiring the helmsman to operate the helm. However, since the helmsman needs to input the steering command from the operating unit to steer the marine vehicle, it is difficult for the helmsman to steer the marine vehicle with the autopilot device in an intuitive manner.